• 한국초전도학회:학술대회논문집
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• 한국초전도학회 1999년도 High Temperature Superconductivity Vol.IX
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• pp.280-290
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• 1999

The microstructures of a Tl$_{0.8}Pb_{0.2}Bi_{0.2}Sr_{1.6}Ca_2Cu_3O_{9+{\delta}}$/Ag tape (tape I ) with J$_c$ of 17,600 A/cm$^2$ at 77 K and 0 T and three Tl$_{0.8}Pb_{0.2}Bi_{0.2}Sr_{1.8}Ba_{0.2}Ca_{2.2}Cu_3O_{9+{\delta}}$/Ag tapes with J$_c$'s of 9,300 (tape II), 16,700 (tape III) and 25,200 A/cm$^2$ (tape IV)prepared using the powder-in-tube method and an in-situ reaction method, were investigated using scanning electron microscopy and high-resolution transmission electron microscopy, and compared each other. ln the tape preparation, an intermediate rolling process was incorporated during final heat-treatment for the last tape, but not for the rest of the tapes. The microstructural analysis revealed clear differences in grain-texturing, crystallographic defects and impurity phases, depending on the chemical composition of the tape. Tendency of directional grain-alignment increased in an order of tapes I, II III and IV. In tape IV, T1-1223 grains are textured, at least in local regions. In crystallographic defects, while stacking faults were prevalent in the former composition, dislocations and voids were frequently observed in the latter. Also impurity phases were appeared to be more abundant in the former than in the latter. The relationship between 1,and the microstructure in the tapes was attempted to explain in a term of grain-linking.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.445-446
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• 2008

In this paper, we investigated the diffraction grating efficiency on Ag-doped amorphous chalcogenide Ag/AsSeS thin film for used to volume hologram. The film thickness was 2 um and diffraction efficiency was obtained from He-Ne (632.8nm) and DPSS(532nm) (P:P) polarized laser beam on Ag/AsSeS thin films. As a result, for the films, the maximum grating diffraction efficiency using He-Ne laser(632nm) is 0.15%[2000sec]. And then The recording speed of DPSS laser was about 40s which of batter than He-Ne lasers.

• 대한임상검사과학회지
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• 제43권4호
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• pp.171-178
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• 2011

Glycated hemoglobin ($HbA_{1c}$) is a most preferably used baseline of diabetes, implicating average blood glucose levels over a 2-3 month period of time. Recently the American Diabetes Association has recommended the $HbA_{1c}$ assay as one of the criteria for diabetes. Although some studies provide data with "estimated average glucose", by converting the $HbA_{1c}$ results from simple linear regression, the results are not applicable to whole diabetes. We compared the relationship between $HbA_{1c}$ and estimated average glucose by anemia degree of diabetic patients in Korea. The data from the 2008~2009 Korean National Health and Nutrition Examination Survey were used. Analysis was done for 1,257 diabetes subjects with $HbA_{1c}$ results. The distribution of subjects was 34.1% in 60's, 25.9% in 70's, 21,6% in 50's, showing that there was more than 80% in over 50's. To take a close look of the differences depending on the anemic degree, we applied WHO criteria (hemoglobin<13.0 in men and hemoglobin<12.0 in women) and divided anemia degree. The regression equation for A1c and estimated average glucose was $eAG_{mg/dL}=24.3{\times}A1c-32.0$ ($R^2=0.54$, p<0.001) in all subjects, $eAG_{mg/dL}=33.1{\times}A1c-96.1$ ($R^2=0.52$, p<0.001) in slight anemia ($11.0{\leq}$Hb<13.0 in men, $10.0{\leq}$Hb<12.0 in women), and $eAG_{mg/dL}=13.5{\times}A1c+34.9$ ($R^2=0.12$, p =0.075) in moderate anemia (Hb<11.0 in men, Hb<10.0 in women). The regression was not significant in moderate anemia. The relationship between HbA1c and eAG was lower correlation than ADAG study, and eAG showed lower value in all ranges among $HbA_{1c}$ 5~13%. Such as a korea where, there are many diabetic patients among the old aged and higher prevalence rate of anemia, we should be extra careful when we reflect eAG using $HbA_{1c}$ and need to establish criteria which can be applicable to koreans.

• 한국미생물·생명공학회지
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• 제26권6호
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• pp.558-561
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• 1998

식용버섯인 버들송이(Agrocybe cylindracea)로부터 새로운 생리활성물질을 탐색하던 중 버들송이 자실체의 methanol 추출물로부터 Diaion HP-20 column chromatography, ethyl acetate extraction 및 silica gel column chromatography를 행하여 AG 8을 분리하였다. 분리된 AG 8의 구조해석을 위하여 Mass, $^1$H 및 $^{13}$C NMR, irradiation실험 및 HMBC를 실시한 결과 분자량이 297, 분자식이 $C_{11}$ $H_{15}$$N_{5}$$O_3$S인 nucleoside계 화합물 5'-deoxy-5'-methylthioadenosine(MTA)으로 동정하였다. AG 8의 지질과산화 저해활성은 $IC_{50}$/ 값이 3.2 $\mu\textrm{g}$/$m\ell$ 이었으며 양성 대조구인 vitamin E보다 3배 정도 낮은 활성을 보여주었다. 본 화합물은 고등동물의 대사과정에 관여하는 효소 대사 조절물질로 고등동물을 비롯한 각종 생물체에 존재하는 것이 보고되었으나 담자균류로부터는 본 연구에 의하여 처음 분리되었다.

• Journal of Applied Biological Chemistry
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• 제60권3호
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• pp.213-218
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• 2017

The objective was to examine the antifungal activity of Pinus densiflora extract for the control of turfgrass fungal diseases. Antifungal activities of the various fractions of n-hexane, methylene chloride (Ch), ethyl acetate (EtOAc), and n-butanol from P. densiflora were evaluated against Rhizoctonia solani AG1-1B, R. solani AG2-2IV, Sclerotinia homoeocarpa, R. cerealis, Pythium spp., and Colletotrichum graminicola. The Ch and EtOAc fractions showed antifungal activity against Pythium sp. and C. graminicola in paper disc assay. The effective concentration to produce 50% mycelial inhibition ($EC_{50}$) using five discriminatory concentrations of pinosylvin (1) from the Ch fraction of P. densiflora was evaluated on R. solani AG1-1B, R. solani AG2-2IV, R. cerealis, and S. homoeocarpa. S. homoeocarpa showed the highest sensitivity with the lowest mean $EC_{50}$ value ($8.426{\mu}g/mL$) among the four pathogens. Among the three Rhizoctonia pathogens, R. cerealis had the highest mean $EC_{50}$ value ($99.832{\mu}g/mL$) and R. solani AG2-2IV, with the lowest sensitivity, had the lowest $EC_{50}$ value ($39.696{\mu}g/mL$). These results suggested that pinosylvin (1) from P. densiflora could be a valuable lead compound in the improvement of a novel antifungal agent.

• 대한화학회지
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• 제35권6호
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• pp.673-679
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• 1991

N-Tert-butylbenzothiazole-2-sulfenamide (TBBS;가황촉진제)의 전기화학적 환원을 직류와 시차펄스 폴라로그래피, 순환 전압전류법, 조절전위 전기량법으로 연구하였다. TBBS의 전극환원과정은 단일 환원파(-2.31 volts vs. Ag/0.1M AgN$O_3$)에서 비가역으로 4전자가 이동하는 E-C-E-C 반응기구로 진행되었다. 조절전위 전기분해 결과 sulfenamide(-S-N=)결합이 끊어지고 mercaptobenzothiazole (MBT)과 유리된 황 그리고 benzothiazole disulfide (MBT dimer) 등이 생성물로 얻어졌다. 생성물의 분석결과와 pH변화에 따른 폴라로그램의 해석을 바탕으로 전기화학적 반응기구를 제안하였다.

• 전기학회논문지
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• 제64권9호
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• pp.1323-1329
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• 2015

The WO₃/Ag/WO₃ transparent thin films are fabricated by the RF magnetron sputtering. This has a transmittance of front and rear about 90% in the visible light range and surface resistance of 6.41Ω/□. In this paper, we analyzed the surface characteristics caused by the working pressure and O₂ plasma surface treatment to apply a transparent electrode that was prepared to the laminated structure with other materials. The working pressure was changed in the WO₃ film to 10mTorr, 7mTorr, and 5mTorr, it showed a lower than roughness of conventional ITO. In addition, by 55.5774 J/m² at 5mTorr, it shows the hydrophobic property with lower process pressure. O₂ plasma surface treatment was changed at the condisions of the RF power to 150W, 100W, and 50W and the process time to 240s, 180s, 120s, and 60s. The surface roughness are the maximum roughness(Rmax) 6.437nm and the average roughness(Rq) 0.827nm at RF power 150W, and the maximum roughness (Rmax) 6.880nm and the average roughness (Rq) 0.839nm at process time 240sec. It showed a lower value than the surface treatment. also about working pressure and process time is increased, it showed the hydrophobic.

• 대한화학회지
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• 제35권6호
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• pp.680-688
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• 1991

N-Oxyldiethylenebenzothiazole-2-sulfenamide (ODBS;가황산촉진제)의 전기화학적 환원을 직류와 시차펄스 폴라로그래피 순환 전압전류법, 조절전위 전기량법으로 연구하였다. ODBS의 전극환원과정은 단일 환원파(-1.86 volts vs. Ag/0.1 M AgN$O_3$in AN)에서 비가역으로 3전자가 이동하는 E-C-E-C 반응 메카니즘으로 진행되었다. 조절전위 전기분해 결과 SULFENAMIDE(-S-N=) 결합이 끊어지고 mercaptobenzothiazole(MBT)과 benzothiazole disulfide(MBT dimer) 그리고 유리된 sulfur 등이 생성물로 얻어졌따. pH 변화에 따른 폴라로그램의 해석과 생성물 분석의 결과를 바탕으로하여 전기화학적 반응 메카니즘을 제안하였다.

• 한국결정성장학회지
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• 제9권2호
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• pp.197-206
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• 1999

수평 전기로에서 $AgInSe_2$다결정을 합성하여 HWE(Hot Wall Epitaxy) 방법으로 $AgInSe_2$ 단결정 박막을 반절연성 GaAs(100) 위에 성장하였다. $AgInSe_2$단결정 박막은 증발원과 기판의 온도를 각각 $610^{\circ}C$, $450^{\circ}C$로 성장하였다. 이때 성장된 단결정 박막의 두께는 3.8$\mu\textrm{m}$였다. 단결정 박막의 결정성의 조사에서 20 K에서 측정한 광발광 스펙트럼은 884.1nm(1.4024eV) 근처에서 excition emission 스펙트럼이 가장 강하게 나타났으며, 또한 이중결정 X-선 회절곡선(DCXD)의 반폭치(FWHM)도 125arcsec로 매우 작은 값으로 측정되어 최적 성장 조건임을 알 수 있었다. Hall 효과는 van der Pauw 방법에 의해 측정되었으며, 온도에 의존하는 운반자 농도와 이동도는 293K에서 각각 $9.58{\times}10^{22} electron/m^3,\; 3.42{\times}10^{-2}m^2/V{\cdot}s$였다. $AgInSe_2$단결정 박막의 광전류 단파장대 봉우리들로부터 20K에서 측정된 $\Delta$Cr(Crystal field splitting)은 0.12eV, $\Delta$So(spin orbit coupling)는 0.29 eV였다. 20K에서 얻어진 광발광 봉우리들 중에서 881.1nm(1.4071 eV)와 882.4nm(1.4051 eV)는 free exciton$E_x$의 upper polariton과 lower polariton인$E_x^U$와 $E_x^L$를 의미하며, 884.1nm(1.4024 eV)는 donor-bound exciton emission에 의한 $I_2$봉우리를, 885.9nm(1.3995 eV)는 acceptor-bound exciton emission에 의한 $I_1$ 봉우리를 각각 나타내었다. 또한 887.5nm(1.3970 eV)에서 관측된 봉우리는 DAP(donor-acceptor pair)에 기인하는 광발광 봉우리로 해석되었다.

• 한국재료학회지
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• 제23권7호
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• pp.379-384
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• 2013

In order to produce size-controllable Ag nanoparticles and a nanomesh-patterned Si substrate, we introduce a rapid thermal annealing(RTA) method and a metal assisted chemical etching(MCE) process. Ag nanoparticles were self-organized from a thin Ag film on a Si substrate through the RTA process. The mean diameter of the nanoparticles was modulated by changing the thickness of the Ag film. Furthermore, we controlled the surface energy of the Si substrate by changing the Ar or $H_2$ ambient gas during the RTA process, and the modified surface energy was evaluated through water contact angle test. A smaller mean diameter of Ag nanoparticles was obtained under $H_2$ gas at RTA, compared to that under Ar, from the same thickness of Ag thin film. This result was observed by SEM and summarized by statistical analysis. The mechanism of this result was determined by the surface energy change caused by the chemical reaction between the Si substrate and $H_2$. The change of the surface energy affected on uniformity in the MCE process using Ag nanoparticles as catalyst. The nanoparticles formed under ambient Ar, having high surface energy, randomly moved in the lateral direction on the substrate even though the etching solution consisting of 10 % HF and 0.12 % $H_2O_2$ was cooled down to $-20^{\circ}C$ to minimize thermal energy, which could act as the driving force of movement. On the other hand, the nanoparticles thermally treated under ambient $H_2$ had low surface energy as the surface of the Si substrate reacted with $H_2$. That's why the Ag nanoparticles could keep their pattern and vertically etch the Si substrate during MCE.